In my opinion you have to deeply involve in crypto to observe the behavior of market because you have to choose a best time to sell your coin.
When you observe a pump after a huge dump than carefully monitor the market & try to sell your coins when market is green and peoples are buying.
The fact is that more cases when there is a real opportunity to sell, this is primarily due to those traders who earn on the price difference. If prices have fallen, then it will definitely be someone who will buy for profit, but for sale it is completely unprofitable.
the conclusion is that when prices go down then it's time to buy and when prices rise they should sell immediately because the market is easy to go back down.
sometimes many people lose the opportunity to get profit because they are too greedy to want big profits so we have to think about it.